Tightening kernel for Mac Mini G4

[Alexey Dokuchaev]

Hi there,

Today I've brought to life an old rusted Mac Mini G4 which was almost thrown
into the garbage.  I've just installed some fresh snapshot of -CURRENT on it,
and now building world.  Before I get to the kernel stage, I have couple of
questions (to minimize the chances of hooking up console again if I screw up
along the way).

I'm used to trimming the kernel config down as much as possible (yes, that
means "nodevice mem" and "nodevice io" at least on i386).  This brings me to
the first question: do I read it correctly that "device io" is x86 specific
and I don't need it on ppc?

Second question is about ATA subsystem.  Per dmesg(8):

  ata0: <Apple MacIO ATA Controller> mem 0x20000-0x20fff,0x8800-0x88ff irq
  24,12 on macio0
  ata1: <Intrepid Kauai ATA Controller> mem 0xf5004000-0xf5007fff irq 39 at
  device 13.0 on pci2
  ada0 at ata1 bus 0 scbus1 target 0 lun 0
  ada0: <TOSHIBA MK4025GAS KA100P> ATA-6 deviceuhub1: 3 ports with 3
  removable, self powered

Normally on x86 I omit ATA stuff completely from kernel config, and just add
ataintel_load="YES" (on pre-AHCI system) in /boot/loader.conf, which in turn
loads all necessary dependencies (atapci.ko, etc.).  Since "ataintel" hardly
applies to my G4: 1) can I remove ATA from my MACMINI kernel config?, and 2)
what shall I add to /boot/loader.conf to enable the disk in Mac Mini G4?  Is
atapci.ko (or simply ata.ko) enough?  I do not see MacIO- or Kauai-related
.ko files under /boot/kernel, hence the question.

Third, about this section of powerpc/GENERIC, seemingly PowerPC-related:

  device          iicbus          # I2C bus code
  device          kiic            # Keywest I2C
  device          ad7417          # PowerMac7,2 temperature sensor
  device          ds1631          # PowerMac11,2 temperature sensor
  device          ds1775          # PowerMac7,2 temperature sensor
  device          fcu             # Apple Fan Control Unit
  device          max6690         # PowerMac7,2 temperature sensor
  device          powermac_nvram  # Open Firmware configuration NVRAM
		  ^^^^^^^^^^^^^^
How is this one related to nvram.ko?  Do I need to add nvram_load="YES" to
/boot/loader.conf to be able to interact with OF nvram from userland?  Do
I have to keep "powermac_nvram" in kernel config at the same time?

  device          smu             # Apple System Management Unit
  device          windtunnel      # Apple G4 MDD fan controller

None of these seems to be modularized, so: which of them are required for
Mac Mini G4?

Fourth question is of less importance, but still.  In powerpc/GENERIC, I
see this sound support section:

  device          sound           # Generic sound driver (required)
  device          snd_ai2s        # Apple I2S audio
  device          snd_davbus      # Apple DAVBUS audio
  device          snd_uaudio      # USB Audio

But nonetheless:

  $ mixer
  mixer: /dev/mixer: No such file or directory

Is internal sound card supported?  If yes, which module should I load?

Thanks,

./danfe